Holder-on



A..HUNTER. l

DER-0N.

APPLICAT ILED MAY 6,1919.

1,341,370, Patented M25, 1920.

@noauto/L UNITED STATES PATENT QFFICE.

.ALBERT HUNTER, OF PORTLAND, OREGON.

HOLDERfON.

Application filed May G, 1919.

To all whom t mayooncern:

Be it known that I, ALBERT HUNTER, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Holders-On, of which the following is a specification.

The present invention relates to improve ments in holders-on for pneumatic tools, or for use in combination with riveting hammers of the air type and this holder-on is designed for the purpose of backing up rivets when driven by long-stroke hammers of the well known type.

The subject matter of the present inven tion, although not confined solely for the purpose, is speciiically adapted for use in ship construction when operating on the metal plates of the hull and other portions of the vessel.

rlhe invention consists essentially in the novel combinations and arrangements with the usual type of holdenon using air or where the ordinary heading is used, and consists of an extensible holder-on shaft that is adjustable to suit the space between the part to be riveted and a fixed or stationary element against which the holder-on may be placed to back up the tool while the rivet operation is being performed.

In the accompanying drawing one complete example of the physical embodiment of the invention is illustrated, the parts being constructed and combined according to the best mode so far devised, for the practical application of the principles of the invention.

Figure 1 is a side view in elevation of an air driven holder-on or pneumatic tool of the usual type equipped with the extensible shaft of the present invention.

Fig. 2 is an enlarged detail view partly broken away for convenience of illustration of the invention as embodiedin the device to be described.

Fig. 8 is a cross section taken on the lines 3*-3 of Fig. 2.

In order to fully illustrate the invention as depicted in the drawing a standard form of holder-on tool 1 of the pneumatic type is shown, which may be used for applying a hammer blow to the head of the rivet by causing a reciprocating piston to come into play, thus counter-acting the tendency of the pneumatic riveter at the other end of Specification of Letters Patent.

Patented May 25, 1920.

serial No. 295,229.

the rivet to drive the rivet back out of its place. This tool is equipped with the usual air connection 2 and the threaded tapered thimble 3 by means of which the holder-on is attached to the extensible shaft 4.

The device of the invention includes a screw bar 4 of suitable dimensions and weight and is screw threaded at one end to be entered and secured in the complementary thimble of the holder-on tool, and the device also includes the extension bar 5 that telescopes over the screw bar and is adjustable thereon longitudinally. The extension bar is preferably a hollow or tubular member as a metallic pipe and is equipped with the threaded head 6 with threads complementary to those upon the bar 4 and these two parts may be extended or collapsed in their relation with each other by turning the extension bar in the proper direction, the extension bar being equipped on its lower end with the usual tool point 7 held fixed by the set screw 8. To provide means to hold the complementary parts 4 and 5 in iixed position a spring supported pin 9 is disposed in the opening 10 through the wall of the extension bar 5 and will register with a longitudinal groove 1l cut lengthwise of the screw bar. The supporting spring 12 for the pin 9 is secured to the extensible member 5 in any suitable means, here shown with the screw, and the spring 12 normally exerts an outward pressure to keep the pin 9 withdrawn.

When an adjustment has been made the pin is inserted and held in position to prel vent turning of the screw bar, or the extension bar by means of a spring keeper 13 which is held adjusted in a groove 14 in the extensible member. The keeper spring is provided with an outwardly turned end 15 to allow it to ride up on the back of the pin 9. A slight turn past this point will serve to keep the pin in place during operation of the tool. Upon the opposite side of the extensible bar is a second spring supported pin 16 carried on the spring arm 17 and this spring arm normally causes an inward pressure on the pin. At the base of the screw in one ofthe grooves is a drilled hole 18 adapted to receive the pin 16 whenever the tool is extended to its limit thus locking and preventing further movement oi' the screw bar or extensible member. In normal working position the pin 16 will ride in the bottom of the thread and will not otherwise affect the operation of the extension bar eX- cept to prevent it going past its limit.

In Fig. 1 the invention illustrates the holder-on in position for use on a ships bot,- tom supported upon the extensible holder and the extensible holder being supported by the block 19, the implement being arranged for use in a vertical position so that the rivet 'set of the tool may be alined with the rivet head to be held. Vhere the necessity for using the tool in a horizontal or angular p0- sition arises, the tool is backed up against the bracing or against the members of the shipway. The extensible holder-on is adjusted to approximately the space to .be occupied and of course pro-vision is made for forcing the rivet set or head to the rivet and it will be readily apparent that the eXtension member when in proper position will perform the function of baeking u the tool with eficiency and satisfaction. *rom the above -description taken in connection with the drawings it is evident that I have provided a devicev that fulfils conditions of a comparatively perfect eXtensible holder-on bar for this purpose as embodied in the following claim.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is The combination with a rivet tool and its threaded screw bar having a longitudinal groove thereon, of a hollenT internally threaded extension bar, a spring supported pin thereon for engaging the longitudinal groove of the screw bar, means for locking the pin in an engaged position, a second spring supported pin engaging the screw bar to limit the extension, a tool point on the lower end `of the extension bar, and means for holding it in adjusted position.

In testimony whereof I aflixmy signature.

ALBERT HUNTER.. 

